Spray pump



Nov. l5, 1938.

SPRAY PUMP A.` R. `THOMPSON ET Al.

Filed June 15, 193e Patented Nov. 15,1938

SPRAY PUMP Albert R. Thompson, Los Gatos, and Roy M. Magnuson, San Jose, Calif., assignors to Food Machinery Corporation, San Jose, Calif., a corporation of Delaware Application June 15, 1936, Serial No. 85,2@

13 Claims.

, disposal of work fluid which leaks past the piston.

Heretofore, to our knowledge, in pumps of the general character referred to, the devices which function to prevent pump uid which leaks past the pump piston from passing along the plunger rod and into the crankcase usually take the form of seal around the plunger rod, as for example, a stuillng box having a packing which is compressed against the rod by means of a gland nut through which the rod works. Such packings wear rapidly, and require frequent gland adjustment and correspondingly frequent replacement. Moreover, even with the most efficient seals of the above character, someliquid leaks past the seal into the crankcase to dilute the oil thereof.

Wear of the character referred to, and the resultant crankcase oil dilution by work iluid which leaks past the pump piston, have formed especial handicaps in the.` spray pump art' in which our invention is especially useful, because spraying pressures are high, and because the spray fluid is usually a corrosive chemical containing particles of solid abrasive material. Thus, any degree of dilution of the crankcase oil results in harmful erosive and corrosive action on the bearing parts of the pump. It is highly desirable, therefore, that such fluids be kept out of the crankcase and away from the bearing parts of a pump.

The above noted disadvantages are substantially eliminated in a pump embodying our invention by the provision of effective means for preventing entry of leakage spray or work iluid into the crankcase, such means comprising preferably a labyrinth baille which is non-Wearing in character ,and which directs leakage work fluid through paths leading away from the crankcas and out of the pump. In a preferred embodiment, the baille may be formed as a cup-shaped member movable with the piston to telescope over the open end of the cylinder, and having a seri'es of annular baffles thereon which telescope within a stationary series of annular baiiles in wiping relation thereto. 50 It is a general object of our invention to provide a pump in which the crankcase is maintained permanently free of work fluid.

' Another object of the linvention is to provide a pump of the character referred to, in which work :duid which leaks past the pump plunger is (Cl. 10S- 202) carried through paths leading away from the crankcase.

Another object of the invention is to provide a pump of the character referred to, in which baille means is provided between the pump cylinder and crankcase to dispose of work fluid which leaks past the pump plunger and thereby prevent entry of such leakage fluid into the crankcase.

Further objects will become manifest to those skilled in the art as the description of a preferred embodiment proceeds in connection with the accompanying drawing, in which:

Fig. 1 is a view in sectional elevation of a pump embodying a preferred form of our invention, the view being taken in a vertical plane through the axis of a pump cylinder;

Fig. 2 is a vertical transverse section taken in the plane of the line 2-2 of Fig. 1.

Our invention is disclosed as embodied ina multi-cylinder high pressure spray pump of the horizontal type, with whichit is especially useful. Generally, the means for disposing of leakage work fluid includes a labyrinth baille which is preferably formed as a cup-shaped shield movable with the piston to telescope over the cylinder,

together with a series of stationary baffles forming a grill around the pump cylinder and open at the bottom, and a series of reciprocating bales forming a grill on the cup-shaped shield which is movable with the pump plunger to telescope over the pump cylinder and within the stationary grill in wiping relation thereto.

Referring to the drawing, the pump includes casing i providing a frame which can be secured in place by suitableconnecting means applied to pads 2. Crankcase portion 3 is formed in casing i at the open end thereof closed by cover 4. Within crankcase portion 3, crank shaft 6 is suit'- ably journaled and is operatively connected by eccentric or connecting rod 1 with crosshead B slidably mounted in cross head guideway 9 formed in casing l As seen in Fig. 2, three cylinders are provided in the pump, but as all are similar, only one will be described.

Each of the cylinders is formed by a liner removably mounted in casing l for cooperation with a piston removably carried by the associated cross head. To dispose of leakage work fluid which passes the piston, a cup-shaped shield is provided for movement with crosshead to telescope over the vcylinder and form labyrinth bafiling.' Also, the casing and shield are each provided with respective series of annular baffles forming4 cooperating grills disposed in wiping relation to control the path of flow of the leakage uid after such fluid leaves the shield. Cylinder I3 (Fig. 1) is removably secured within boss I4 of casing I and has cylinder head I6 secured thereon. Cylinder head I6 is provided with closure I1 and also conventional intake and discharge ball check valves I3. Any suitable connecting means may be provided for mounting cylinder I3 on casing I in axial alignment with crosshead guideway 9. The piston comprises packing 2I suitably clamped in packing retainer` 22, which is secured by stud 23 on extension 24 of crosshead 8.

For the purpose of preventing entry of leakage fluid into the crankcase, the crosshead is provided with a cup extension forming a shield which extends over and telescopes the pump cylinder and is provided around its exterior with spaced apart annular ribs or baffles forming a grill movable in telescopic relation with respect to stationary annular baffles on casing I forming a grill which is concentric with the cylinder. Crosshead 8 has cup-shaped extension 3I provided with a series of annular ribs 32. Extension 3| is positioned `between cylinder I3 and a series of stationary annular bailles 33 formed within casing I by a series of transverse apertured walls 34, one of which is seen in Fig. 2. Walls 34 are connected and braced by bracing webs 36 which are spaced apart to provide openings 31 directly below each cylinder I3. Only a slight clearance is provided between baflles 32, 33 so that they are disposed in wiping relation.

In operation, the reciprocation of the piston from crank shaft 6 draws the work fluid in past one valve I8 and out past the other in the usual manner. Any leakage work fluid passing the piston is discharged from cylinder I3 into the baille cup formed by cylindrical extension Vor skirt 3I from which it can only pass out through the peripheral space between skirt 3| and cylinder I3, from which it is discharged between'bailles 33 and through ports 31. It will be noted that most of such fluid will be discharged through the left most ports 31 as seen in Fig. I and that the annular spaces between respective baffles 32, 33 provide blind paths for disposing of any fluid caught therebetween without the possibility 4of such fluid being carried back into the crankcase. 'I'he cooperating bailles 32, 33 during their relative reciprocation, effect removal of any work fluid from ballles 32 onto and past baffles 33.

Because of the close cooperating wiping relation between baffles 32, 33, there ls no possibility of an air current to carry fluid or vapor back toward the crankcase. Thus, baffles 32 on skirt 3| tend to entrain such mist and fluid as overhangs skirt 3|, as well as to sweep drops from the overhanging portions of baffles 33 and deposit such fluid in the grooves between bailies 32 so that such fluid flows around and down to the lower side of skirt 3I. Any drops of fluidhanging from bailles 32 are wiped oil by the lower portions of baffles 33, and such fluid passes through apertures 31 and out of the pump. As stated above, the greater portion of fluid escapes through the left hand ports 31, the residue rapidly diminishing during the intake stroke as the ports toward the right are progressively reached by the rim of skirt 3|.

It will be noted that bales 32 on skirt 3I are so spaced apart that bailles 32 in their movement alternately open and substantially close the spaces between baffles 33. This construction appears to aid in preventing fluid from passing in the direction of the crankcase since the fluid has substantially ne free path longitudinally of' the cylinder. It is also to be noted that in the furthest displacement of skirt 3i in the discharge stroke of the piston, end baille 32 adjacent crosshead 8 is still positioned to the right oi' the adjacent end baille 33. It will be seen also that the y labyrinth construction presents a relatively large fluid receiving space and large related surfaces whereon fluid may collect and that even a very large amount of leakage fluid will be deflected by the same, and positively directed away from the crankcase.

Having described a preferred embodiment of our invention and explained the principle thereof, it will be apparent that the same may be variously embodied by those skilled in the art, and it is to be understood, therefore, that We consider ourselves entitled to all such modifications as fall within the purview of the claims.

We claim:

1. In a horizontal spray pump; a casing having a crankcase, a cylinder, and axguideway therein; a piston in said cylinder; a crosshead carrying said piston and mounted for reciprocation in said guideway; a series of annular bailles in said casing around said cylinder and spaced therefrom; a baffle skirt on said crosshead and telescoping over said cylinder and within said series of balies; and a series of annular bailles on said skirt in wiping relation with said first-named series of bailles.

2. In a pump, a casing provided with a. crankcase portion, a piston and cylinder. receiving chamber, and a crosshead guideway therebetween; said piston and cylinder receiving section further providing a series of spaced baille forming Walls coaxially apertured to form a cylinder space; a pump cylinder in said space in spaced relation to and coaxially of said series of baille forming walls; a crosshead mounted for movement in said guideway; a piston on said crosshead and extending into working relation with said pump cylinder; a. deflector skirt secured to the crosshead and extending in the direction of said piston and telescoping over said cylinder and within said apertured walls; and a series of annular baffles on said skirt for movement along and in close proximity to the surfaces of said baille forming walls.

3. In a pump, a cylinder, a piston therein, a crosshead therefor, means for driving said crosshead, and baille means carried by the crosshead and telescoping over the cylinder for preventing travel of piston leakage along the crosshead toward said driving means.

4. In a horizontal pump, a cylinder, a working piston therein, and a labyrinth baille associated with said cylinder for disposing of fluid leaking past said piston, said baille comprising a reciprocative section having a series of annular baiiles, and a stationary section having a series of annular baflles surrounding the path of movement of said reciprocative section.

5. In a horizontal pump, a casing, a cylinder in said casing, a piston in said cylinder, operating means for said piston comprising a crosshead, a series of annular bales coaxial with said cylinder, a deilector skirt on said crosshead and disposed to reverse the flow of leakage from the pump cylinder, and disposed to sweep past said bailles upon reciprocation of said crosshead.

6. In a horizontal pump, a casing, a cylinder in said casing, a piston in said cylinder, operating means for said piston comprising a crosshead, a series of annular baffles coaxial with said cylinder, a deflector skirt on said crosshead and disposed to reverse the flow of leakage from the pump cylinder and having a series of 'annular baflles disposed to sweep past said first-named baiiles upon reciprocation of said crosshead.

7. In a horizontal spray pump, aA crankcase, a cylinder, a working piston in said cylinder, an annular baille grill surrounding said cylinder in spaced relation therefrom, and a cup-shaped member movable with said piston and telescoping over said cylinder and within said grill.

8. In a horizontal spray pump, a crankcase, a cylinder, a Working piston in said cylinder, an annular baiile grill surrounding said cylinder in spaced relation therefrom, and a cup-shaped member movable with said piston and telescoping over said cylinder and within said grill, said member having an annular baille grill disposed in wiping relation with said first-named grill.

9. The combination with a horizontally disposed pump cylinder having a piston working therein, and a guide bearing for said piston, of a cup-shaped member movable with the piston and telescoping said cylinder in spaced relation therefrom to provide a labyrinth baille for controlling the ow of leakage work uid to direct such uid away from said guidel bearing.

10. The combination with a horizontally disposed pump cylinder having a piston working therein, of a cup-shaped member movable with the piston and telescoping said cylinder in spaced relation therefrom to provide a labyrinth baille for controlling the iiow of leakage work fluid, and means for receiving and directing such uid away from said member.

11. -A device for preventing leakage fluid from passing from a cylinder-piston assembly to the power drive thereof comprising means forming a recessed chamber'surrounding vthe cylinder of the pump andprovided with a series of parallel spaced baiile plates, and baille means mounted for reciprocation. with the piston and forming a labyrinth baille with said baille plates.

12. In a pump, a cylinder, a piston therein,

a cup-shaped member movablewith said piston and telescoping over said cylinder, and means in wiping relation Awith the exterior of said cupshaped member for receiving and directing leakage uid away from said member.

13. In a pump, a cylinder, a piston therein, a cup-shaped member movable with said piston and telescoping over said cylinder, and a series of bales in wiping realtion with the exterior of said cup-shaped member for removing leakage fluid therefrom.

ALBERT R. THOMPSON. ROY M. MAGNUSON. 

